How many ideas or dreams will you go theough before you finally pick one and stick with it?
The answer is unknown until you are proud to answer the more important question: What is it that you do for a living?
Often we think we need to find exactly what it is we are pssionate about rifht away. This is not always the case. Some people have to go through an experimental stage. Others have to lose it all and hit ground zero first. The ones that are a little more aware or faster already know from an early age what they have been called to do in life.
Personally I still question from time to time what my calling really is. Whatever it is for you, keep fighting to see it become a daily reality for you.
Of course you should make sure you can get through what seth godin calls The dip before wasting years and years of valuable time.